THE historic Portsmouth navy base faces closure with the loss of more than 17,000 jobs.

Defence Secretary Liam Fox is ­studying shock plans to phase out the main home of Britain’s surface fleet over the next decade.

It would save the cash-strapped Government £200million a year.

The future of the base – Portsmouth’s biggest employer – is a key question in a defence review due to be completed by the end of the year.

Britain’s other major naval bases – Devonport in Plymouth and Faslane in Scotland – are safe as unlike Portsmouth they are essential for ­nuclear subs.

A senior Whitehall defence source said: “The blueprint for closing Portsmouth is drawn and ready to go. Labour did consider it but ruled it out on political grounds as it would cost too many jobs.”

Closing the base – a naval port for 800 years and home to Nelson’s flagship Victory – would cost the local economy £680million. About 17,200 work on the base and a further 18,000 jobs would be threatened.

Two thirds of the Navy’s surface fleet is based in Portsmouth, including the aircraft carriers Ark Royal, Illustrious and Invincible, six destroyers, six ­frigates and eight minesweepers.

The ships would go to Faslane and Devonport. Faslane is home to the UK’s nuclear deterrent while Devonport is the only site equipped to do refits on Vanguard nuclear subs which carry Trident missiles.

Portsmouth had hoped the cloud hanging over its future had lifted after work on building parts for two new £4billion supercarriers started there earlier this year.

HMS Queen Elizabeth is due to enter service in 2014 and HMS Prince of Wales two years later. Both were to be based at Portsmouth.

Mr Fox must now decide whether to complete the work at Portsmouth ­dockyard before it shuts or move it to one of the five other shipyards in the programme.

Former local Labour MP Sarah McCarthy-Fry branded the closure plans “a betrayal of the people of Portsmouth”.

The Government wants to find £20billion a year from public spending cuts and higher taxes.

Chancellor George Osborne expects the MoD to cut its running costs by 25 per cent cut.

Even the future of the RAF is in question. A merger with the Army and Royal Navy could save on administration.

Military land will be sold off. The ­defence source said: “The MoD owns one-and-a-half per cent of the country so there’s plenty which it can do without.”

Mr Osborne will tomorrow slash quangos and scrap government pilot projects to save an initial £6billion.

A £7.5billion order for new inter-city trains is in the balance and the building of extra lanes on motorway hard ­shoulders could be halted. And a £12billion NHS programme to computerise patient records may be trimmed.

An MoD spokesman said: “We will undertake a fundamental review of the way we provide defence capability.”